Portable electronic device with a graphical user interface



FIG. 1 is a front view of a portable electronic device with a graphical user interface in a longitudinal direction showing our new design; and,

FIG. 2 is a front view of another embodiment of a portable electronic device with a graphical user interface in a longitudinal direction showing our new design.

The broken lines showing the portable electronic device and portion of graphical user interface, which illustrate environment structure, form no part of the claimed design. 

CLAIM We claim the ornamental design for a portable electronic device with a graphical user interface, as shown and described. 